Gas phase transformation of fluorinated benzoporphyrins to porphyrin-embedded conical nanocarbons.

Geodesic nitrogen-containing graphene fragments are interesting candidates for various materials applications, but the available synthetic protocols, which are required to overcome the intrinsic strain energy during the formation of bowl-shaped skeletons, are often incompatible with heteroatom-embedded structures. In this mass spectrometry-based gas phase study, we present by means of collision-induced dissociation experiments and supported by density functional theory calculations, the first evidences for the formation of a porphyrin-embedded conical nanocarbon. Influences of metalation and functionalization of the utilized tetrabenzoporphyrins were investigated throughout, which resulted in different cyclization efficiencies, different ionization possibilities and a variation of the dissociation pathway. Our results suggest a concerted cyclization mechanism for the  fjord -region HF-elimination, which supports a selective pathway towards bent nitrogen-containing graphene fragments.